The following trigger with the associated audit table will keep track of db object changes:

use DatabaseName
go
create trigger DBObjectMonitor
on dbo.sysobjects
for insert, update, delete
as
insert SysobjectsAudit
select getdate(), isnull(deleted.name,''), isnull(inserted.name),''),
isnull(deleted.type,''), isnull(inserted.type),'')